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    <title>Document</title>
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    <script>
        //JS5一共有六种数据类型，JS6又新加两种
        //三种基本数据类型
        var num = 10;
        var name = "李华";
        var flag = true;

        //引用对象类型，object
        var user = {
            age: 10, n: "LiHua", f: false

        }

        //两种空类型
        var hello = null;
        var world = undefined;

        // typeof用来判断数据类型，一般用来判断三种基本的类型
        console.log(typeof num);
        console.log(typeof name);
        console.log(typeof flag);
        console.log(typeof user);
        console.log(typeof []);
        console.log(typeof null);
        console.log(typeof undefined);
        

    </script>
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